The PEC performance of BiVO₄ was enhanced by preparing the CoFeB_i/BiVO₄ photoanode using an ultrafast photoassisted electrodeposition method

BiVO4 is a promising material for water oxidation due to its suitable physical and chemical properties. However, the BiVO4 film has limitations such as poor electron transport, surface charge recombination, and low catalytic activity, which affect its performance. To address these issues, under light assistance (AM 1.5G), we employed a simple electrodeposition method to selectively react the film for only 10 seconds in a 1 M potassium borate electrolyte (pH = 9.5) containing iron and cobalt sources. This method allowed for the fast loading of bimetallic borate compounds onto the vanadium-bismuth oxide photoanode, resulting in efficient photoelectrochemical (PEC) water splitting. The modification of the BiVO4 electrode through this process reduces the electron-hole composite rate, thereby improving PEC performance, photocurrent, and oxygen release. The CoFeBi/BiVO4 photoanode demonstrated a significant photocurrent density of 4.4 mA cm(-2) at 1.23 V vs. RHE, which is approximately 2.6 times higher than that of BiVO4. This improvement can be attributed primarily to the synergistic effect of the cobalt-iron-based cocatalyst, which exhibits outstanding water oxidation activity through its Fe3+ and Co2+ active sites. This work introduces a new research pathway for applications in photovoltaics and photoelectrochemical water splitting.